1. Field of the Invention
Embodiments of the invention relate to exchanging rich communication (RCS) capability information in a communications system.
2. Description of the Related Art
Wireless communication systems have developed through various generations, including a first-generation analog wireless phone service (1G), a second-generation (2G) digital wireless phone service (including interim 2.5G and 2.75G networks) and third-generation (3G) and fourth-generation (4G) high speed data/Internet-capable wireless services. There are presently many different types of wireless communication systems in use, including Cellular and Personal Communications Service (PCS) systems. Examples of known cellular systems include the cellular Analog Advanced Mobile Phone System (AMPS), and digital cellular systems based on Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), the Global System for Mobile access (GSM) variation of TDMA, and newer hybrid digital communication systems using both TDMA and CDMA technologies.
More recently, Long Term Evolution (LTE) has been developed as a wireless communications protocol for wireless communication of high-speed data for mobile phones and other data terminals. LTE is based on GSM, and includes contributions from various GSM-related protocols such as Enhanced Data rates for GSM Evolution (EDGE), and Universal Mobile Telecommunications System (UMTS) protocols such as High-Speed Packet Access (HSPA).
Access networks using various communication protocols (e.g., 3GPP access networks such as W-CDMA, LTE, etc., or non-3GPP access networks such as WiFi, WLAN or wired LAN, etc.) can be configured to provide Internet Protocol (IP) Multimedia Subsystem (IMS) services via an IMS network managed by an operator (e.g., Verizon, Sprint, AT&T, etc.) to users across a communications system. Users that access the IMS network to request an IMS service are assigned to one of a plurality of regional application servers or application server clusters (e.g., groups of application servers that serve the same cluster region) for supporting the requested IMS service.
Rich Communications Suite (RCS) is a recently developed service-type in the IMS domain. RCS permits users to query device capabilities and/or application-level multimedia capabilities from their contacts, such that a client device can update the capabilities of the contacts in its address book in real-time and thus enable “rich communication”, such as Voice over LTE (VoLTE), video calls, Instant Messaging (IM), file or image sharing, etc., based on the real-time capabilities of the contacts. In the current RCS standard, user equipments (UEs) (or client devices) send a UE-to-UE (or peer-to-peer) Session Initiation Protocol (SIP) OPTIONS message to one or more target UEs to request the UE-specific RCS capabilities of the target UEs. The SIP OPTIONS message includes the RCS capabilities of the transmitting UE, and the SIP OPTIONS message prompts the target UE to respond to the SIP OPTIONS message with a SIP 200 OK message that indicates the RCS capabilities of the target UE. Thus, the exchange of the SIP OPTIONS and SIP 200 OK messages is a peer-to-peer handshaking process that is mediated by the IMS network and by which both endpoints update their respective RCS capabilities for the other endpoint.
For example, UE 1 can send a SIP OPTIONS message to UE 2 over an IMS network that indicates UE 1's RCS capabilities and requests UE 2 to respond back to UE 1 with an indication of the RCS capabilities of UE 2, UE 1 can send a SIP OPTIONS message to UE 3 over the IMS network that indicates UE 1's RCS capabilities and requests UE 3 to respond back to UE 1 with an indication of the RCS capabilities of UE 3, and so on. UE 2 then responds to the SIP OPTIONS message from UE 1 with a SIP 200 OK message that indicates UE 2's RCS capabilities, UE 3 responds to the SIP OPTIONS message from UE 1 with a SIP 200 OK message that indicates UE 3's RCS capabilities, and so on.
In the current IMS standard, different UEs (e.g., a cell phone, a tablet computer, a desktop computer, etc.) can be registered to the same user for IMS service. However, in the current IMS standard, a UE that is registered to the same user as another UE does not necessarily have contact information for uniquely addressing the other UE.